Composting

 

   – Converting Palm Oil Mill Wastes to Fertilizer Enriched Compost

 

                                                                   - By Amit Guha

 

 

Asiagreen’s system of generating compost from mill wastes can be seen operating at the Serdenak Palm Oil Mill in Johor. Mr Steven Chong, Asiagreen’s Managing Director, walked members of the plantation industry through the composting process.

 

 Visitors saw the workings of the hammer mill machinery that is interfaced to the palm oil mill and which shreds the incoming EFB into fibres prior to its being strip laid (windrowed) on flat to gently sloping well drained terrain.

 

 POME is then sprayed on the windrowed compost piles before being covered by plastic sheets to prevent wetting from rain so as to allow for aerobic decomposition (and to prevent anaerobic conditions).  Boiler Ash, Kernel Shells and Mesocarp Fibres can also be mixed into the compost piles upto a maximum of 5 to 7 % due to their alkalinity.  The compost pile takes about 2 -3 months to mature and in the process loses 75% by volume.

 The piles are periodically turned by the use of a moving mechanical device on tracks to promote uniform aeration in the composting process.

 

 About 1 to 2 weeks prior to maturity, cultured soil microorganisms and beneficial mycorhizzae are added to the compost heaps to make the compost biologically active (important for a plants uptake of phosphorus especially).  Mineral fertilizers are also added to the compost a few weeks before maturity to enrich the composts nutritional value for end use  - in oil palm plantings or other end uses.

 

 On maturity, the compost is ready for application in the field in oil palm estates by a mechanical spreader or for other end uses – landscaping, golf courses, horticulture etc.

 

 In oil palm cultivation, the application of such mineral fertilizer enriched compost using mill wastes / by products allows for the industry to practice an environmentally friendly closed cycle ZERO WASTE operation – that is economic.   Only one application a year is required if fertilizer enriched compost is applied in volume – a big boon where labour availability is a problem! Furthermore, leaching losses of nutrients are minimal, and water is better conserved in the soils. If the composts’ nutrient content can be tailored / matched to the plantings requirement based on the species nutrient balance requirements, the agronomic justification of using mineral fertilizer enriched compost to replace the direct application of mineral fertilizers is there.  And it might be economically justifiable as well.

 

 Asiagreen’s Steven Chong informs that the Capital Cost for setting up a composting system is about RM 2 million – to generate 3000 tons of compost at a cost of RM 56 / ton. Assuming 7 to 8 tons of such compost needs to be applied per hectare per year, this would come to about RM 450 / ha / yr. If the compost is enriched by mineral fertilizers by about RM 200 / Ha / yr, it would mean a total cost of RM 650/ha/yr. This would be comparable to current fertilizer expenditure levels by oil palm estates. And there would also be no mill waste to get rid of by applying fertilizer-enriched compost.

 

Perhaps estates with mills might want to look further into this?

 

More information on this is available at Asiagreen’s web site: www.asiagreen.com.my

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